Calcium chloride is hygroscopic which means it has the ability to draw moisture from the air. So, if it were used I suppose it could aid somewhat in keeping the track surface moist. I have no idea if it is illegal to apply to race tracks or why it would be since it is applied to roads and sold routinely in bags to melt ice on sidewalks (as it mixes with water an endothermic reaction occurs which means heat is generated and that also helps melt the ice).